Re: Spinosaur Variation

["Jaime A. Headden" <qilongia@yahoo.com>]

I wrote:

<<The rarity of fossils other than teeth in Africa for
these critters would suggests a relative low density
population any given area. Gadoufaoua was certainly
more populous spinosaur-wise than Baharija (Egypt) or
the Tafilalt and Kem Kem (Morocco), yet we have only
one good specimen. Very wet, temperate, very like the
southern US in summer at its more agreeable times. The
north was both cooler and more forested, being able to
support giant titanosaurs as well as bigger spinosaurs
and carnosaurs/abelisaurs/whateverosaurs. This
suggests a less radiating role in the function of the
sail.>>

  My attempt at Paleoecology.

Josh Smith replied, putting his granite gavel down
hard on the table:

<OK.
 First:  Considering that the records at the Egyptian
Geological Survey in Cairo only record three German
expeditions that went to Bahariya (the Oasis, where
the type locality of the formation crops out) and that
only one of them was actually focused entirely on the
Bahariya Formation itself, and considering that most
of the data regarding these German expeditions failed
to survive the 1940s, and considering that there are
no active dinosaur paleontologists in Egypt today and
considering that no one (almost--see forthcoming
posting) has played in Bahariya in 50 years, I don't
really think we should be making claims about the
theropod population density of the paleo western
desert.>

  It was my understanding that the Baharija was spread
out over the Egyptian, Tunisian, and Algerian Tethyan
coast in the Berr to Apt-Alb. Fossils ascribed to
Spinosaurus are strewn across much either
contemporaneous or above- or lowere-lying strata, but
I did not realized that the Baharija was best confined
to the type locality. My appologies.

<Second: What is the deal with everyone running around
saying that the western desert was cool and forested?
What little paleoclimatic data exists for that area
(and it isn't bloody much, folks) is highly 
speculative at best. I didn't see a lot of stuff that
I would call data to supported cool, temperate
forests.>

  For my part, it was from my understanding that the
Tegama Group, Cameroonian formations I forget the
names (or name) of, and the Kem Kem and Tafilalt were
mudstones and siltstones, with fauna depicting a very
estuarine and partially lacustrine environment,
coupled with the estimated mean temperature of the
region and its equatorial location at the time period,
that it was similar to the Lousianan, east Texan,
Alabaman to Floridian environments. I read these, in
Sereno et al. (1994, 1996, 1998), Russell (1996), and
Taquet (1998), and thus fell to my perceptions that
Everglades and Okavango Delta were not too far from
what these places may have been like. When I said
"temperate ... forested" I did not clarify my meaning,
and confused the term "temperate": "equitorial" or
"semi-equitorial" (compared to today) are better terms
and are what I was thinking of, and forested as in
broad stands of trees, not like conifer forests of
Canada, Europe, and America. The Moroccan habitats
would have to have some great forests or such to
support the *Aegyptosaurus* that tromped around out
there.

 -------

  A clarification: when I estimated the snout fragment
(from Taquet, 1984 and Taquet and Russell, 1998) as
alluding to an animal with a 2.2m skull, that was the
top size measurement, while a 1.9m skull may be a bit
more conservative and easier to deal with.

  Jaime
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